<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
-->
<svg xmlns="http://www.w3.org/2000/svg">

  <title>SourceAlpha pseudo input reference</title>

  <defs>
    <filter id="blur">
      <feGaussianBlur in="SourceGraphic" stdDeviation="2"/>
    </filter>
  </defs>

  <g fill-opacity="0.6" stroke="black" fill="black" stroke-width="3" filter="url(#blur)">
    <circle cx="98" cy="85" r="25"/>
    <circle cx="80" cy="110" r="25"/>
    <circle cx="116" cy="110" r="25"/>
  </g>
</svg>
